Discrete VLF wave emissions in association with auroral light intensity fluctuations have been recorded at L=4 during simultaneous operation of a broadband VLF receiver and a low light level TV system. The correlated wave-particle interaction events are interpreted as being typical examples of the electron cyclotron resonance process responsible for the precipitated of energetic electrons in the vicinity of the plasmapause. A range of delay times between the correlated VLF wave and the optical signals, coupled with the frequency versus time characteristics of the VLF wave emissions, is consistent with the electron cyclotron source region being randomly located within 8000 km of the equatorial plane. The events are shown to be triggered by ducted whistler mode waves that originate from the opposite hemisphere to that of the station at which the observations are made. Events characterized by VLF waves of rising tone are presumed to occur in a region of enhanced plasma density commonly observed within the plasma trough. It is proposed that this region is responsible for ducting the VLF waves from the source to ground. ¿ American Geophysical Union 1990